Janice Singh's presentation on Visualization of Monitoring Data at the NASA Advanced Supercomputing Facilityuting facility.
The presentation was given during the Nagios World Conference North America held Sept 20-Oct 2nd, 2013 in Saint Paul, MN. For more information on the conference (including photos and videos), visit: http://go.nagios.com/nwcna

3.
Why Visualization is Needed
• 24 x 7 Help Desk
– need a quick overview of system status
• but still more specific than nagios visualization
– not just single status per host, but sub-groups per host
– they assess situations before calling next level of support
• automatic alerts from nagios are not as selective
– interrelated issues
• allows us to see how many systems affected by one issue
Janice Singh - janice.s.singh@nasa.gov 3

9.
Nagios (and add-ons) setup
The Basics
•the webserver and the main nagios server are the same machine
•there is a network firewall called “the enclave”
– most compute nodes are inside the enclave
– the webserver can only receive data from the enclave, not
send
•the servers within the enclave send nagios data to the webserver
via nsca
•for the servers outside the enclave, nrpe is used
•plugins written in Perl using Nagios::Plugin
Janice Singh - janice.s.singh@nasa.gov 9

10.
Nagios (and add-ons) setup, cont.
Versions
•when I inherited the systems, they were all using nagios 2.10
– most systems have been upgraded to nagios 3.4+
– all new systems have nagios 3.5
– webserver is still using 2.10
•nsca 2.7.2 across the board
Janice Singh - janice.s.singh@nasa.gov 10

11.
Nagios (and add-ons) setup, cont.
Clusters within the enclave
•there is one host that is considered the Dedicated Nagios Server
•the rest of the hosts are monitored using nrpe
•exceptions on Pleiades:
– there are many hosts monitored that get reimaged often
• difficult to administer nrpe
• use check_by_ssh
– ssh is flaky under nagios 3, so it still uses nagios 2.10
• will randomly give the error: Could not open pipe: /usr/bin/ssh
– use 2 Dedicated Nagios Servers
• so many checks that there was unacceptable latency
– tests that should run every 2 mins were running every 30
mins
Janice Singh - janice.s.singh@nasa.gov 11

12.
datagg (DATa AGGregator)
• why it was needed (i.e. what nagios couldn’t do for us)
– error summaries of nagios problems
• the nagios webpage does tell number of alerts per service
group, but that cannot be leveraged via API
Janice Singh - janice.s.singh@nasa.gov 12

14.
datagg (DATa AGGregator), cont.
• why it was needed (i.e. what nagios couldn’t do for us)
– mapping service nodes to the appropriate Lustre filesystem
• they are in a servicegroup (but not available via API)
Janice Singh - janice.s.singh@nasa.gov 14

15.
datagg (DATa AGGregator), cont.
• in-house written perl script
– it reads the command file (pipe) that nsca creates on the
webserver
– the nagios configuration on the webserver also writes to the
nsca command file
– it aggregates the data that it reads in from the pipe and writes
it out to a flat file referred to as the “HUD buffer”
• The data read in is in the format:
[$timestamp] PROCESS_SERVICE_CHECK_RESULT;
$hostname; $service_description; $state; $output
Janice Singh - janice.s.singh@nasa.gov 15

16.
HUD Buffer
• is a Windows-style .ini file
– sections
• used to group together the boxes (or sub-boxes)
• ex: [pleiades daemons]
– keys
• name=value
– this is where we put the nagios state and output of
plugin
– every section also has the key Error Summary
Janice Singh - janice.s.singh@nasa.gov 16

18.
Displays
• Two versions
– Internal (aka Staff HUD) on the internal network
• Staff HUD and nagios web interface
• clicking on Staff HUD goes to the nagios web page
– for the service checks for the host or service group
– the nagios web interface gives more details on the
plugin output than is displayed on the HUD
– the nagios web interface is used to suspend/restart
notifications
– External (aka miniHUD)
– Permissions set in the Apache config file
• Both written in Perl using cgi-bin
Janice Singh - janice.s.singh@nasa.gov 18

19.
Future Plans
• use a database to collect data
– this will also allow us to have historical data beyond what is in
the logs, which can be used in graphing
– will eliminate the need for a flat file
Janice Singh - janice.s.singh@nasa.gov 19

20.
Future Plans
• things that would be great to see in nagios 4
– an API
– make a nagios check run “on demand”
– no more random “could not open pipe” errors
– lower latency (we’re having problems with less than 600
checks!)
– error summaries
– way to send large amounts of data via nsca
– a way to see the exact command that nagios ran on the
nagios webpage
Janice Singh - janice.s.singh@nasa.gov 20